Investigating Electron Screening effects on α-decay

An open problem in Nuclear Astrophysics concerns the understanding of electron-screening effects on nuclear reaction rates at stellar energies. In this framework we have proposed to investigate the influence of the electron cloud on α-decay by measuring Q-value and α-decay half-lives of fully stripped, H-like and He-like ions. These kinds of measurements have being feasible just recently for highly-charged radioactive nuclides by fragmentation of 238U at relativistic energies at the FRS-ESR facility at GSI [1,2]. In this way it is possible to produce, efficiently separate and store highly-charged α-emitters. Candidates for the proposed investigation were carefully selected and will be studied by using the Schottky Mass Spectroscopy technique [2]. In order to establish a solid reference data set, lifetimes measurements of the corresponding neutrals have been performed directly at the FRS, by implanting the separated ions into an active Silicon stopper. Results will be reported.(author)